A film-coated tablet, also referred to as a film-coating tablet or a film-coat tablet, is a preparation obtained by coating the surface of a plain tablet (uncoated tablet) obtained by compression filling a powder or the like with a film comprising a water-soluble polymer(s) or the like. The purpose of coating a plain tablet with a film is, for example, to protect the plain tablet from external light, atmosphere (humidity and oxygen) or the like, to mask the taste, smell or the like of the medicinal agent contained in the plain tablet, to enhance the appearance of the tablet and the like.
On the other hand, there is a scored tablet (also referred to as “dividing tablet”) provided with a groove called a “score line” on the surface of a plain tablet. The purpose of providing the score line is to enable a tablet to be easily divided by applying a force to the tablet by a human in order to adjust the dose or the like.
As for a general constitution of the scored tablet (an embodiment of the score line), for example, a detailed description is given in Patent Document 1 or the like.
However, as a result of a detailed study about the divisibility of conventional scored tablets conducted by the present inventors, although various embodiments with respect to general scored tablets in which only a score line is provided on a plain tablet have been proposed, they found that there was a problem as described below in the embodiment in which a score line is provided further on a film-coated tablet, and that a sufficient study about the score line from the viewpoint of dividing the film-coated tablet in such a manner that the film coincides with the plain tablet was not made.
The problem found by the present inventors is a problem that the coating film on the surface of the tablet is not divided along the score line as intended.
That is, in the case where a film-coated scored tablet 100 as shown in FIG. 10(a) is divided along a score line 200, as shown in FIG. 10(b), a plain tablet portion 101 is divided as intended at the bottom of the groove of the score line 200 as the start point. However, a film 102 is not always divided as intended at the bottom of the groove of the score line, and as shown in FIG. 10(b), the film is peeled off from the surface of the plain tablet in the vicinity of the bottom of the groove, and finally, it is ripped and divided into two at a position leaned toward either divided piece in the end. Further, as a region denoted by the reference numeral 300 in FIG. 10(b), also in a back side portion corresponding to the score line, unintended peeling and ripping of the film occur on the surface of the plain tablet. Even in the case where a score line is provided on the back surface side, the same phenomenon as in the score line of the upper surface shown in FIG. 10(b) occurs.
As described above, when such a conventional film-coated scored tablet is divided, around the divided surface of the divided piece, only the film protrudes from the plain tablet or the film is torn and the surface of the plain tablet is exposed. In either case, it is not preferred in terms of appearance.